Artificial light sources often produce heat. Most lamps convert only part of the input energy into visible light, with the remaining energy being wasted as heat. For example, a large portion of the electricity used by artificial light sources, such as traditional incandescent, fluorescent, and high intensity discharge (HID) lamps and new light-emitting diode (LED) lights, is converted to heat.
Light-emitting diodes (LEDs) may be predominant in buildings and transport infrastructure for illumination and signaling in the near future. LEDs have small size, long life, and relatively high luminous efficacy, enabling various new applications in illumination and signaling. LEDs are expected to displace many traditional artificial lamps and light sources used in existing buildings and transport infrastructure.
The drawings illustrate only example embodiments and are therefore not to be considered limiting of the scope of the embodiments described herein, as other embodiments are within the scope of this disclosure. The elements and features shown in the drawings are not necessarily drawn to scale, emphasis instead being placed upon clearly illustrating the principles of the embodiments. Additionally, certain dimensions or positionings may be exaggerated to help visually convey certain principles. In the drawings, similar reference numerals between figures designate like or corresponding, but not necessarily the same, elements.